// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.

#include <xaudio2.h>
#include "AudioCommon/AudioCommon.h"
#include "AudioCommon/XAudio2Stream.h"
#include "Common/Event.h"

#ifndef XAUDIO2_DLL
#error You are building this module against the wrong version of DirectX. You probably need to remove DXSDK_DIR from your include path.
#endif

struct StreamingVoiceContext : public IXAudio2VoiceCallback
{
private:
	CMixer* const m_mixer;
	Common::Event& m_sound_sync_event;
	IXAudio2SourceVoice* m_source_voice;
	std::unique_ptr<BYTE[]> xaudio_buffer;

	void SubmitBuffer(PBYTE buf_data);

public:
	StreamingVoiceContext(IXAudio2 *pXAudio2, CMixer *pMixer, Common::Event& pSyncEvent);

	~StreamingVoiceContext();

	void StreamingVoiceContext::Stop();
	void StreamingVoiceContext::Play();

	STDMETHOD_(void, OnVoiceError) (THIS_ void* pBufferContext, HRESULT Error) {}
	STDMETHOD_(void, OnVoiceProcessingPassStart) (UINT32) {}
	STDMETHOD_(void, OnVoiceProcessingPassEnd) () {}
	STDMETHOD_(void, OnBufferStart) (void*) {}
	STDMETHOD_(void, OnLoopEnd) (void*) {}
	STDMETHOD_(void, OnStreamEnd) () {}

	STDMETHOD_(void, OnBufferEnd) (void* context);
};

const int NUM_BUFFERS = 3;
const int SAMPLES_PER_BUFFER = 96;

const int NUM_CHANNELS = 2;
const int BUFFER_SIZE = SAMPLES_PER_BUFFER * NUM_CHANNELS;
const int BUFFER_SIZE_BYTES = BUFFER_SIZE * sizeof(s16);

void StreamingVoiceContext::SubmitBuffer(PBYTE buf_data)
{
	XAUDIO2_BUFFER buf = {};
	buf.AudioBytes = BUFFER_SIZE_BYTES;
	buf.pContext = buf_data;
	buf.pAudioData = buf_data;

	m_source_voice->SubmitSourceBuffer(&buf);
}

StreamingVoiceContext::StreamingVoiceContext(IXAudio2 *pXAudio2, CMixer *pMixer, Common::Event& pSyncEvent)
	: m_mixer(pMixer)
	, m_sound_sync_event(pSyncEvent)
	, xaudio_buffer(new BYTE[NUM_BUFFERS * BUFFER_SIZE_BYTES]())
{
	WAVEFORMATEXTENSIBLE wfx = {};

	wfx.Format.wFormatTag       = WAVE_FORMAT_EXTENSIBLE;
	wfx.Format.nSamplesPerSec   = m_mixer->GetSampleRate();
	wfx.Format.nChannels        = 2;
	wfx.Format.wBitsPerSample   = 16;
	wfx.Format.nBlockAlign      = wfx.Format.nChannels*wfx.Format.wBitsPerSample / 8;
	wfx.Format.nAvgBytesPerSec  = wfx.Format.nSamplesPerSec * wfx.Format.nBlockAlign;
	wfx.Format.cbSize           = sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX);
	wfx.Samples.wValidBitsPerSample = 16;
	wfx.dwChannelMask           = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT;
	wfx.SubFormat               = KSDATAFORMAT_SUBTYPE_PCM;

	// create source voice
	HRESULT hr;
	if (FAILED(hr = pXAudio2->CreateSourceVoice(&m_source_voice, &wfx.Format, XAUDIO2_VOICE_NOSRC, 1.0f, this)))
	{
		PanicAlertT("XAudio2 CreateSourceVoice failed: %#X", hr);
		return;
	}

	m_source_voice->Start();

	// start buffers with silence
	for (int i = 0; i != NUM_BUFFERS; ++i)
		SubmitBuffer(xaudio_buffer.get() + (i * BUFFER_SIZE_BYTES));
}

StreamingVoiceContext::~StreamingVoiceContext()
{
	if (m_source_voice)
	{
		m_source_voice->Stop();
		m_source_voice->DestroyVoice();
	}
}

void StreamingVoiceContext::Stop()
{
	if (m_source_voice)
		m_source_voice->Stop();
}

void StreamingVoiceContext::Play()
{
	if (m_source_voice)
		m_source_voice->Start();
}

void StreamingVoiceContext::OnBufferEnd(void* context)
{
	//  buffer end callback; gets SAMPLES_PER_BUFFER samples for a new buffer

	if (!m_source_voice || !context)
		return;

	//m_sound_sync_event->Wait(); // sync
	//m_sound_sync_event->Spin(); // or tight sync

	m_mixer->Mix(static_cast<short*>(context), SAMPLES_PER_BUFFER);
	SubmitBuffer(static_cast<BYTE*>(context));
}

HMODULE XAudio2::m_xaudio2_dll = nullptr;
typedef decltype(&XAudio2Create) XAudio2Create_t;
void *XAudio2::PXAudio2Create = nullptr;

bool XAudio2::InitLibrary()
{
	if (m_xaudio2_dll)
	{
		return true;
	}

	m_xaudio2_dll = ::LoadLibrary(XAUDIO2_DLL);
	if (!m_xaudio2_dll)
	{
		return false;
	}

	if (!PXAudio2Create)
	{
		PXAudio2Create = (XAudio2Create_t)::GetProcAddress(m_xaudio2_dll, "XAudio2Create");
		if (!PXAudio2Create)
		{
			::FreeLibrary(m_xaudio2_dll);
			m_xaudio2_dll = nullptr;
			return false;
		}
	}

	return true;
}

XAudio2::XAudio2()
	: m_mastering_voice(nullptr)
	, m_volume(1.0f)
	, m_cleanup_com(SUCCEEDED(CoInitializeEx(nullptr, COINIT_MULTITHREADED)))
{
}

XAudio2::~XAudio2()
{
	Stop();
	if (m_cleanup_com)
		CoUninitialize();
}

bool XAudio2::Start()
{
	HRESULT hr;

	// callback doesn't seem to run on a specific CPU anyways
	IXAudio2* xaudptr;
	if (FAILED(hr = ((XAudio2Create_t)PXAudio2Create)(&xaudptr, 0, XAUDIO2_DEFAULT_PROCESSOR)))
	{
		PanicAlertT("XAudio2 init failed: %#X", hr);
		Stop();
		return false;
	}
	m_xaudio2 = std::unique_ptr<IXAudio2, Releaser>(xaudptr);

	// XAudio2 master voice
	// XAUDIO2_DEFAULT_CHANNELS instead of 2 for expansion?
	if (FAILED(hr = m_xaudio2->CreateMasteringVoice(&m_mastering_voice, 2, m_mixer->GetSampleRate())))
	{
		PanicAlertT("XAudio2 master voice creation failed: %#X", hr);
		Stop();
		return false;
	}

	// Volume
	m_mastering_voice->SetVolume(m_volume);

	m_voice_context = std::unique_ptr<StreamingVoiceContext>
		(new StreamingVoiceContext(m_xaudio2.get(), m_mixer.get(), m_sound_sync_event));

	return true;
}

void XAudio2::SetVolume(int volume)
{
	//linear 1- .01
	m_volume = (float)volume / 100.f;

	if (m_mastering_voice)
		m_mastering_voice->SetVolume(m_volume);
}

void XAudio2::Update()
{
	//m_sound_sync_event.Set();

	//static int xi = 0;
	//if (100000 == ++xi)
	//{
	//    xi = 0;
	//    XAUDIO2_PERFORMANCE_DATA perfData;
	//    pXAudio2->GetPerformanceData(&perfData);
	//    NOTICE_LOG(DSPHLE, "XAudio2 latency (samples): %i", perfData.CurrentLatencyInSamples);
	//    NOTICE_LOG(DSPHLE, "XAudio2 total glitches: %i", perfData.GlitchesSinceEngineStarted);
	//}
}

void XAudio2::Clear(bool mute)
{
	m_muted = mute;

	if (m_voice_context)
	{
		if (m_muted)
			m_voice_context->Stop();
		else
			m_voice_context->Play();
	}
}

void XAudio2::Stop()
{
	//m_sound_sync_event.Set();

	m_voice_context.reset();

	if (m_mastering_voice)
	{
		m_mastering_voice->DestroyVoice();
		m_mastering_voice = nullptr;
	}

	m_xaudio2.reset(); // release interface

	if (m_xaudio2_dll)
	{
		::FreeLibrary(m_xaudio2_dll);
		m_xaudio2_dll = nullptr;
		PXAudio2Create = nullptr;
	}
}